Classification of insular-basal ganglia gliomas based on the displacement of corticospinal tracts evaluated by diffusion tensor imaging.

Background: Resection of insula-basal ganglia (IBG) gliomas is challenging because of their deep location and vicinity to critical structures, whereas diffusion tensor tractography (DTT) can noninvasively delineate the tracks of white matter fibers. This study aims to evaluate the role of cortico-spinal tract (CST) positions in prediction of the prognosis of patients with IBG gliomas.
Methods: We retrospectively reviewed 34 patients with IBG gliomas. DTT was used to reconstruct the CSTs for all patients, and the IBG gliomas were classified into three types (type I-III) based on the shifted patterns of the CSTs.
Results: The number of patients with type I IBG gliomas was 12 (35.3%), which was equal to the number of patients with type II IBG gliomas, and 10 cases (29.4%) presented with type III IBG gliomas. The six-month KPS score was significantly lower in the type III IBG group than that in the type I group (t=-11.43, P=0.013) and the type II group (t=-9.97, P=0.033). Postoperative MRI demonstrated that gross total or near total resection was achieved in 76.5% (26 cases) of all of the patients.
Conclusions: The results suggest that the proposed classification of IBG gliomas can be used for predicting the long-term postoperative outcome profiles of IBG glioma patients.